1. Field of the Invention
The present invention relates to a film image reading apparatus and, more particularly, to a film image reading apparatus which projects an image of a light transmission original such as a film onto a reading sensor and sequentially converts image data into electrical signals.
2. Related Background Art
A film image reading apparatus of this type radiates light onto a film surface of a positive or negative film, transmission light from the film is projected onto a reading sensor by an optical system, and electrical signals from the reading sensor are read as image data. The reading sensor comprises a line image sensor of, e.g., a CCD. The sensor mechanically scans a projection surface to obtain image data on the entire surface of the film. In general, a film is mounted on a slide mount, and is then set at a predetermined position of the film image reading apparatus. Thus, image reading can be executed without directly touching the film.
However, in the conventional film image reading apparatus of this type, film originals must be set at the predetermined position of the reading apparatus one by one, resulting in poor operability. In order to read a plurality of film originals, each film must be set for every reading operation. In order to solve this problem, a so-called automatic changer in which a plurality of slides for a slide projector for projecting an image of a slide onto a screen are set on a slide tray, and are sequentially and automatically fed and projected may be applied to the film image reading apparatus. However, when the automatic changer with the conventional structure is used, a reading operation is executed regardless of the presence/absence of slides. When no slide is set, the apparatus may read blank as image data, thus posing a new problem.
In general, a slide mount has a square (about 50 mm.times.50 mm) frame having a central rectangular (about 22.5 mm.times.34.3 mm) aperture in which a film is fitted. When a film is mounted on an image reading apparatus, the slide mount must be set at a length or width position in correspondence with a rectangular reading area. If the slide mount is set at a wrong position, an image may be omitted or a black frame of a slide mount may be read.
When an image to be read is prevented from being omitted at both the length and width positions, the black frame of the slide mount is undesirably read.
When an image signal obtained by reading a film is supplied to an external recording apparatus and is printed on a recording paper sheet, if the direction of the recording paper does not match with the set direction of the slide mount, a film image cannot fall within the recording paper sheet, resulting in omission of an image.